Mortgage payoff
Mortgage calculator with extra payments
See when your mortgage could be paid off and how much interest you might avoid by adding monthly, yearly, or one-time principal payments.
What the payoff estimate tells you
This tool answers a specific question: if extra money is applied to your current mortgage principal, how might your payoff time and remaining interest change? The two payoff times and interest totals use the same regular payment, so the difference isolates the extra-payment plan. It does not estimate the full monthly housing bill. For taxes, homeowners insurance, PMI, and HOA dues, use the monthly mortgage payment calculator.
How this calculator works
Enter the principal balance from your latest statement, your mortgage note rate (not APR), and the remaining term. If your statement shows the regular principal-and-interest payment, enter it in the optional field; do not include escrow, taxes, insurance, or PMI. Otherwise, the calculator derives a payment from your balance, rate, and remaining years. It then compares that schedule with extra principal payments. You can combine monthly, annual, and one-time amounts. Annual amounts are applied at the end of each 12-month period; the one-time amount is applied immediately, before the next monthly interest charge.
The formula
The base payment uses the standard amortization formula: P = B × r × (1+r)^n / ((1+r)^n − 1), where B is balance, r is monthly rate, n is months. Each month, interest is added to the remaining balance and the payment is subtracted until the balance reaches zero.
For each later month, the model computes interest = remaining principal × annual rate / 12, subtracts the regular payment and any extra principal, and stops when the balance is paid. It caps the final payment at what is owed. Interest saved is the difference between the two projected interest totals. If you enter your actual regular principal-and-interest payment, that figure drives both schedules; remaining years are then used only when the payment field is blank. An entered payment that cannot retire the loan within the model's 50-year limit produces no payoff estimate.
Worked example
Suppose your current balance is $285,000, the note rate is 6.75%, and 27 years remain. The estimated required principal-and-interest payment is about $1,914 per month. Try an extra $200 each month, then compare it with $2,400 paid at the end of each year. The timing changes the interest calculation, even when the yearly extra total is the same. These are illustrative inputs, not a current market rate or a lender quote.
Why extra mortgage payments save so much
In this model, each principal payment reduces the balance on which later monthly interest is calculated. The result depends on the remaining term, rate, timing, and whether you keep making the extra payments. The savings shown assume you hold the mortgage until payoff; selling or refinancing sooner changes the result.
Pay extra or invest the cash?
This is one of the most common mortgage questions. The trade-off:
- Paying extra can avoid future interest at your note rate while this loan remains outstanding. It also moves cash into home equity, which may be harder to access. Fees, refinancing, selling, and taxes can change the comparison.
- Investing keeps the money in a different asset with uncertain returns, taxes, fees, and risk. Compare the after-tax outcomes and the value of keeping cash available.
Review expensive debt, cash reserves, and any employer retirement match before committing extra cash to a mortgage. The mortgage versus investing guide walks through the broader decision.
Before you schedule extra payments
- Check the loan documents for a prepayment penalty. The CFPB explains that a penalty may apply to some large or full early payoffs. Ask your servicer how your particular loan works.
- Confirm how the extra payment is posted. The CFPB notes that extra principal payments may be permitted. Check your next statement for the actual principal reduction.
- Keep an emergency fund liquid — home equity is hard to access quickly if you lose income.
- Use your real payment schedule. Escrow, mortgage insurance, ARM changes, and recasts are not modeled. This calculator assumes a fixed rate and unchanged required principal-and-interest payment.
Related tools & guides
- Planning a new home purchase? Use the mortgage payment calculator with PMI and taxes to estimate the full monthly housing budget; this payoff tool excludes those costs.
- Using this tool: How to use an extra payment mortgage calculator.
- Also paying for a car? Read where to put an extra payment first.
- Deciding to buy at all? See the Rent vs Buy Calculator.
- Full picture of assets and debts: the Net Worth Calculator.
- Higher-interest debt first: the Debt Payoff Calculator.
Common questions
Does one extra payment each year save the same as monthly extras?
Not exactly. At the same annual total, monthly extra payments usually start lowering principal sooner. Enter the same yearly amount both ways to compare timing.
Will my required mortgage payment fall?
Usually an extra principal payment shortens the loan rather than lowering the contractual payment. Ask the servicer whether a recast is available if lowering the required payment is your goal.
Can I use this as a biweekly mortgage calculator?
No. This model applies the regular payment monthly and does not simulate 26 half-payments a year or their posting dates. A servicer may hold a partial payment until it adds up to a full periodic payment, so do not assume each half-payment immediately reduces principal. Ask your servicer whether it accepts a biweekly plan, when each payment is credited, and whether it charges a fee. The CFPB explains partial-payment handling.
Why might my servicer's payoff date differ?
Payment posting dates, daily interest conventions, escrow, fees, rounding, and loan terms can differ from this monthly planning model. Your statement and servicer's payoff quote control the real amount owed.
Sources and review
- CFPB: principal-and-interest versus total monthly payment.
- CFPB: mortgage servicing and extra principal payments.
- CFPB: prepayment penalties.
- CFPB: partial payments and suspense accounts.
WealthScope Hub maintains this calculator. The formula and assumptions above are visible, and corrections can be sent to wangsuperyu@outlook.com. No individual financial credential or third-party review is claimed. See the editorial policy and About page.
Important note
This estimate assumes a fixed interest rate, monthly accrual, unchanged regular principal-and-interest payment, and every extra amount applied to principal as scheduled. It excludes escrow, taxes, insurance, mortgage insurance, prepayment penalties, ARM changes, recasts, fees, biweekly posting, and lender-specific rules. Educational estimate only; see our disclaimer.